Expansion joint for concrete roads



Patented July 23, 1935 UNITED STATES PATENT OFFICE EXPANSION JOINT FOR CONCRETE ROADS Frederick S. Fleckenstein, Syracuse,

N. Y., as-

signor to The Barrett Company, New York, N. Y., a corporation of New Jersey No Drawing. Application August 28, 1929,

' Serial No. 389,106

U 6 Claims... (01. 94-48 vention is directed to the formation of expansionjoints in concrete or like pavements in which expension and contraction of the concrete is to be provided for by expansion and contraction joint material preferably arranged to form strlpsat spaced intervals in the concrete pavement.

The invention comprehends methods of filling the spaces or voids formed in concrete pavements and the like, and the resultant concrete structures. The term voids as used herein is intended to include expansion joint spaces provided in the road or other similar pavement by the usual spacing of the slabs of concrete as laid and also the cracks .and spaces formed in the concrete after it is cured and which must be filled by suitable waterproof composition to prevent the entrance of liquid such as water thereinto. Entry of water beneath the concrete slabs results in a softening or washing away of the usual earth foundation for the concrete, leaving it unsupported and liable to crack and crumble when subjected to traffic or other loads.

One object of this invention is to provide a plastic waterproof composition which can readily be 'appliedto the expansion joint spaces or other voids in concrete roads and which results in an improved concrete pavement adhering firmly to the concrete so that upon contraction of the concrete slabs the filler follows the concrete and fills the voids and upon expansion of the slabs the filler remains in the voids and does not flow out therefrom. Another object is to provide such filler which can readily and efficiently be applied to the voids in the concrete road while the filler is cold, i. e., a filler which will not require preheating before application to the voids in the concrete. Other objects and advantages of this invention will appear from the following detailed description. 1

Heretofore, expansion joints for concrete roads have been provided in either of two ways. One involved leaving a space between sections of the concrete as laid, this space being filled with joint material by pouring it while hotinto the joint space and allowing it to set therein. lihe other way was to furnish premolded or preformed joint material which was installed between the concrete sections. Usually the joint material was first applied to the foundation for the concrete and then the concrete poured between the joints.

Expansion joints and fillers for voids in concrete roads must be designed to compensate for expansion .and contraction of the concrete. At warm temperatures the concrete expands, subjecting the joint to severe pressure from the sides and unless the joint is properly prepared the 5 joint material will ooze out of the joint and spread itself on thesurface of the concrete where it will be picked up by passing trafiic and spread over the road. Further, in cold weather concrete contracts causing the formation of larger 10 joint spaces or voids. Unless the joint material has an inherent quality of expanding from within it will not fill up the voids, permitting entry of water thereinto with consequent impairment of the concrete road.

In concrete road building it has been found that expansion joints, prepared in either of the two ways above mentioned, have a comparatively short life, the joint material oozing out of the joint space and being picked up by traflic, it be- 20 ing necessary to fill the joint spaces several times during one season. Further, such joints involve economic waste in their application. Pouring hot joint material necessitates provision of heating equipment at the point of application of the 5 expansion joints, thus materially increasing the cost of preparation and application of such joints. The use of preformed or premolded joints, in addition to the cost of the molding equipment for the joints, involves the expense of 30 packing'and shipping the joints to the point of application.

In contra-distinction to these joints, this invention provides waterproof plastic joint fillers which may be applied while cold, requiring no 35 preheating, and which will not run or ooze under the concrete slabs or out of the joint spaces and will expand or contract as the concrete slab contracts or expands, respectively, and thus completely fill and waterproof the joint spaces at all 40 times.

I have found that a filler comprising a bituminous base admixed with fibrous material is admirably suited for the formation of expansion joints in concrete roads and for the filling 45 of voids in concrete pavements. The bituminous base may be coal tar, refined'coal tar, coal tar pitch or asphalt. A voltatile solvent or thinner such as light coal tar oil or volatile mineral oils is added to the bituminous material for the purpose of making it more readily applicable and causing the filler to set rapidly after it is applied to the voids in the concrete. If a coal tar base is utilized, preferably a coal tar oil solvent is admixed therewith. On the other hand, if an as- 55 phalt base is employed it may be thinned with either a mineral oil or a coal tar solvent or thinner. Instead of adding the solwnt or thinner to the bituminous material the latter may be formed containing the desired amount of thinner or solvent, i. e., thecoal tar or other starting ma-. terial may be distilled to drive off some of the oils but leave sufficient light oils to act as a thinner. To the base containing the solvent or thinner is added asbestos or other fibrous material, such as mineral wool, flax-tow, shredded roofing felt. The fibrous material reduces the tendency of the resultant composition to flow when subjected to temperature increases.

A preferred plastic composition which I have found admirably suitedfor the formation of expansion joints in concrete roads contains at least 50% by weight of bituminous material, such as asphalt, having a softening point of from 105 to 120 F. (ball and ring) but may contain from 50 to 60% of asphalt, from 20 to 25%, preferably about 23%, mineral or coal tar oil or other volatile thinner or solvent and from 18 to 25%, preferably about 21%, based on the total weight of the composition as formed, of asbestos or other fibrous material. As illustrative of other plastic compositions which might be used for the formation of expansion joints for filling the cracks in concrete roads the following are noted: Plastic compositions comprising at least 55% by weight of coal tar pitch or other like bituminous material having a softening point of from to F., preferably 95 F. (cube in water), to which is added from 10 to 15% coal tar oil solvent having a boiling point of to 200 C. The amount of coaltar pitch in this composition may vary from 55 to 65% by weight based on the total weight of the composition as formed. From 20 to 30% by weight of asbestos or other fibrous material, preferably approximately 25%, based on the total weight of .the composition as formed, is added to the bituminous base. Also from 1 to 2% of pine tar oil may be added as a deodorant to this plastic composition.

The plastic composition is formed by first thinning the bituminous material base by the addition of the solvent. Fibrous material such as asbestos together with the deodorant if desired, are then added and the mix heated slightly, preferably not above F., and thoroughly agitated to form a substantially homogeneous mixture. Heating of the mix should be kept below temperatures which might cause substantial loss of the volatile solvent or thinner.

A composition which in practice has been found to be suited for forming expansion joints in concrete roads consists of approximately 56% asphalt, 23% solvent therefor and 21% asbestos. This plastic composition when set, due to evaporation of the solvent, will usually be found to have the following percentage composition: 73% asphalt and 27% asbestos.

When employing plastic compositions containing from 50 to 60% asphalt the resultant joint or filler will be found to contain from 6'7 to 78% asphalt and 22 to 33% asbestos.

The plastic composition of this invention is preferably applied cold to the voids in the concrete substructure, i. e., just as packed and taken from the container and without preheating. Preferably, it is extruded as for example by means of any well known type of grease gun provided with a nozzle of the same shape as the joint space so that the material issuing therefrom completely fills the joint space. If desired,

the plastic composition may, by air or other pressure means, be forced into the voids and joint spaces in the concrete structure.

It is of course to be understood that the proportions of the various ingredients stated in the foregoing examples are capable of variations to adapt the product for special conditions and use.

The term "residual bituminous material as employed in the claims is to be understood'as including coal tar residue or refined coal tar residue, coal tar pitch, asphalt or other bituminous material which, as will be apparent to those skilled in the art, is the equivalent of the materials herein specifically set forth. Bythe term coal tar residue as used in the preceding sentence and in the claims, it is intended to include coal tar recovered from a coal distillation plant with or without distillation of such tar to remove oils therefrom, which tar is of a consistency similar to that of asphalt or coal tar pitch.

I claim:

1. The method of forming an expansion joint between slabs in a pavement, which comprises substantially completely filling the expansion joint space with an extrudable plastic composition having a-base of residual bituminous material, fibrous material and volatile solvent, the said plastic composition being introduced between the slabs without heating or preheating, whereby upon evaporation of the said solvent the resulting material fills the joint space and expands or contracts as the said slabs contract or expand.

2. The method of forming an expansion joint between slabs in a pavement, which comprises substantially completely filling the expansion joint space with a plastic composition having a base of bituminous material from the group: coal tar residue, refined coal tar residue, coal tar pitch and asphalt containing undistillable residue which would remain in the still after the coal tar, refined coal tar, coal tar pitch and asphalt, respectively, were subjected to distillation; admixed with fibrous material and with solvent for the bituminous material, the said plastic composition being introduced without being preheated and, upon evaporation of the solvent, forming an expansible mass, filling the joint space.

3. The method of forming an expansion Joint between slabs in a pavement, which comprises substantially completely filling the expansion joint space with a plastic composition comprising at least 50 per cent of bituminous material from the group: coal tar residue, refined coal tar residue, coal tar pitch and asphalt containing undistillable residue which would remain in the still after the coal tar, refined coal tar, coal tar pitch and asphalt, respectively, were subjected to distillation; admixed with fibrous material and with solvent for the bituminous material, the said plastic composition being introduced without being preheated and upon evaporation of the solvent forming an expansible mass, filling the joint space.

4. The method of forming an expansion joint between concrete slabs in a concrete pavement which comprises extruding into and substantially completely filling the joint space with a cold plastic composition having a base of bituminous material from the group: coal tar residue, refined coal tar residue, coal tar pitch andasphalt containing undistillable residue which would remain in the still after the coal tar, refined coal tar, coal tar pitch and asphalt, respectively, were subject'ed to distillation; admixed with fibrous material and with a volatile solvent for the bituminous material. v

5.--The method of forming an expansion joint between concrete slabs in a concrete road, which comprises extruding into and substantially completely filling the joint space with a cold plastic composition comprising at least 50 per cent bituminous material from the group: coal tar residue, refined coal tar residue, coal tar pitch andasphalt containing undistillable residue which would remain in the still after the coal tar, re-

fined coal tar, coal tar pitch and asphalt, respectively, were subjected to distillation; admixed with a volatile solvent for the bituminous material and with fibrous material.

6..The method of forming an expansion joint between concrete slabs in a concrete road, which comprises extruding into and substantially completely filling the joint space with a cold plastic composition comprising at least 5,0per cent asphalt, 20 to 25 per cent of volatile solvent, and 18 to 25 per cent asbestos, the said constituents of the plastic composition being substantially homogeneously admixed. 4

- FREDERICK S. FLECKENS'I'EIN. 

